The USG has no need to falsely accuse North Korea in order to step up it's cyber warfare game. Stuxnet did that a long time ago and was started under the Bush administration.
The reveal of Stuxnet was before the reveal of the reach our surveillance apparatus has. The narrative was one of plausible deniability and a nod to the fact that nations were engaging in offensive online attacks.
The NK hack was an attack on American culture and values. It was symbolic in a way that attacking Iranian civilian nuclear power plants isn't. It also doesn't involve exposing and admitting to running offensive campaigns on civilians of countries we aren't at war with.
NK hack says that we need cyber defense front, since the internet is the new land bridge across the Atlantic and Pacific for anti-American extremists to attack us directly.
It fits the narrative that the measures we are taking regarding near total electronic surveillance are justified and warranted. It also is a call for more funding and power to the agencies that are engaging in the activities.
That said, from another point of view, monumental fuck-up is a consistent feature of many human endeavours.